Lock nut and method of manufacture



April 18, 1933.

I E. L. RUPF LOCK NUT AND MBTHOD,OF MQNUFACTURE Original Filed Feb. 8, 1952 ll W I mm Patented Apr. 18, 1933' I nitnasr L. Run", or wEsr NEW BRIGHTON, NEW YORK LOCK uu'r AND ary 8, 1932, Serial Original application flled Febru June 15, 1932. 8

relates to a locking or d of manufac- This invention gripping nut and to a metho turing same.

This is a division of my copending application Serial hid/591,583, filed Feb. 8, 1932.

The prior art contains disclosures of numerous lock nuts which however are not'in general use because of various manufacturing difliculties, constructional faults and defects which prevent their adaptability for all kinds of work.

The nut and method of manufacturing same which are the subject of my invention,- lend themselves readily to low cost quantity production and are extremely eflicient for their respective purposes. The nut is only slightly difierent in appearance from the standard nut and has the full strength of the standard nut, not being weakened byslits, grooves or under cuts. The nut can be used wherever a standard nut is usable, can be taken off and on a reasonable number of times without losing its locking ability, does' not injure its own threads or the threads of of the bolt and yet is efiicient in its locking action, and can be manufactured from a standard nut by a single pressing or s'tamp- 7 ing operation. I

These and other features of the invention will in part be obvious and in part will more" fully appear from the following description and the accompanying drawing which, however, must be considered as merely illus-' 'trating one form of the invention and in no way limiting it to the embodiment shown and described.

In the drawing:

Fig. 1 illustrates the method of treating a standard nut to makea lock nut.

Fig. 2 also illustrates the method showing I v the, parts in a more advanced position and .using a slightly different die.

Figs. 3 to 6 inclusive are -tional and face views ofvariousform'sof lock nuts. e

In carrying out myinvention I may and prefer to, start with a standard nut 2 which may have any of the usual shapes, holes or threads. Square and hexagonal nuts are illustrated but other forms may be used.

" tion 8 Which causes a axis in the direction of wave ' When the bolt is screwe g suflicient to damage the threads different sec-,

nirrrnon or MANUFACTURE No, 591,683. Divided and this application filed erial No. 617,276.

This nut is placed under a die or tool 4 having a bevelled portion 6' or an arcuate porflow of the metal at the contacting portion of the nut when the twov are forced together. The tool 4 may and preferably does, have a skirt or nut-bodysupporting portion 10 which engages the sides'of the nut to prevent the metal from flowing outwardly. \Vhen the die and the nut are brought into pressure contact, the 6 metal of the nut flows away from the die that. is, both inwardly at 12 toward the axis of the nut and along the hole at 14 parallel to the I movement of the die, giving a slight depression eral face of the nut The die presses a cha nfer or bevel 16 which lies. at an angle tothe lateral face 18 and a longitudinal face 20. As a result of the metal movement, the threads are'given a slight wave 22 and the 70 hole is somewhat flattened at 24 opposite the points wherethe die and nut contact. he d portions of the threads that is, the a portion of the surface of the hole which is distorted tapers "at 26 from the lateral surface 18 toward the original diameter and circular form of wall. It will benoted particularly byreference to Figs. 31) and 30 that not only are the threads wavedandflattened by the pressing operation, but there is likewise a rolling over or angular displacement of the threads themselves, which may be referred' to as a. protrusion eifect, whereby the rolled over threads will be caused to grip the threads of the bolt with a firm fit whereby B accidental removal of the nut is avoided. d into the nut there is a gradual locking effect due both to the Wave of the threads and the protrusion of the "parts, but neither the thread-wave nor 1 the flattening effect nor the protrusion efl'ect of the bolt. By thismethod of treating the nut by the die parts 6 o'r Sand using the skirt 10 of the'diewhere necessary to prevent eneral distortion of the nut the above e cots are obtained, but the hole itself is not made oval in shape-and thus therd are no ends which are spread away from the threads of the bolts. All threads on the bolt and nut at 15 in the latouter faces distorted to such an extent that made to bind the threads or for the entire depth of the 'h nut of course has less The nut is e operation nor are the the hole is barely not weakened by th a wrench will'be unusu'ally loose or tight when applied to the nut in any position.

The angle of the bevelled portion 6 of the die may vary considerably but is preferably from 35 to 50 against the axis of the nut. These angles have been found to give a good correlation of thread wave, protrusion and hole flattening thus utilizing in combination the resilience of the threads of both the nut and bolt as well as the binding action of the flattened hole. By regulating the angle for displacing the and the depth of pressing, the nut can be for only a small fraction of nut, or to a point 27 approximately half way down the nut. It is consideredpreferable to have the die contact with the top of the nut. Thus the threads at the bottom of the nut are not distorted and the nut starts easily on the bolt.

Several advantages are obtained by having the die move along the axis of the nut to compressthe nutlongitudinally instead of laterally. One advantageous: feature is that the hole is distorted only slightly. I The lateral strength than longitudinal'strength and if the nut is compressed from the sides the tendency is for the hole to flatten and leave the threads at their usual angle, but if the die is bevelled and the motion is along the axis, the wave is put in the threads and there is less flattening of the hole although the amount of each can be scribed.

- Another advantage is v the force longitudinally of the nut, a single and very simple and inexpensive die ma be used and the nut may be treated by a single operation.

made to compress one or any number of the faces, either entirely across as is shown in Figs. 5 and- 6, or only part wayacross as is shown in Figs. 3 and 4.

Although a form of nut and method of described in detail,

been made. It is recognized that the invention may be applied to still other forms of nuts and it is therefore desired that the invention be construed as broadly as the claims taken in conjunction with the prior art, may

allow; L

I claim: 1. The method of converting a standard nut into a lock nut which comprises dis-- placing the metal at the periphery of the hole, both inwardly toward the axis of the nut and longitudinally of the nut by pressmetal' wherein. a .portion .of the regulated as previously dethat by exerting eral face.

3. A method as set forth in claim-1 wherein the pressing operation is performed on opposite sides of the lateral face to displace the metal at the perfiphery of the hole on opposite sides thereo 4. The method asset forth in claim 1 wherein the bevel formed makes an angle of from substantially 35 to substantially 50 with the longitudinal axis of the nut.

he method as set forth in claim 1 thread of the nut over during the distplacis partially rolled at the periphery o the ing of the metal ole. v

6. The method as set forth in claim 1 wherein the metal of the outer longitudinal face of the nut adjacent the bevel is retained against expansion during the pressing operation.

In testimony whereof, I affix my signature.

' "ERNEST L. RUPF.

The die may easily be 7 

